Cherokees voted yesterday to expel descendants of black slaves they once owned, a move that has exposed the unsavoury role played by some Native Americans during the Civil War and renewed accusations of racism against the tribe.

Members of the Cherokee Nation, the second largest Native American tribe, voted by 77 per cent to 23 in a special election to amend their constitution and limit citizenship to those listed as “Cherokee by blood”.

The move stripped tribal membership from freedmen – those descended from slaves – and blacks who were married to Cherokees. They have enjoyed full citizenship rights for 141 years.

Opponents of the vote denounced it as a racist plot to deny tribal revenue – which includes $22 billion a year from casino takings for all US tribes – to those not deemed full-blood Cherokee, and to block them from claiming a slice of the tribal pie.

Supporters say that it was a long-overdue move by Cherokees to determine their own tribal make-up. Freedmen were granted full tribal membership under an 1866 treaty that the tribe was essentially forced to sign with the US Government after the Civil War ended.

The vote has reopened a lesser-known chapter in Native American history – the fact that some of the country’s largest tribes sided with the Confederacy during the Civil War – and the intra-tribal racial tensions that have persisted since Emancipation.

Cherokees, Choctaws, Chicksaws, Creeks and Seminoles were known as the Five Civilised Tribes because they adopted many of the ways of the Confederate South, including the ownership of black slaves. The election has also high-lighted the massive gambling revenues many tribes now enjoy because, as “sovereign nations”, they are free to build casinos on tribal lands in a country where gambling is largely illegal.